Unlike every haftarah covered earlier in this account, this reading is not selected because of any specific content shared with Parashah Matot, whose own material concerns the laws of vows, the war against Midian, and the tribes of Reuben and Gad settling east of the Jordan. Jeremiah's opening commissioning has no direct thematic overlap with any of that material at all.
The real reason for the pairing is calendar position rather than content: this is the first of the Three Haftarot of Affliction, a fixed sequence read on the three Sabbaths leading up to Tisha B'Av, the fast commemorating the destruction of both Temples, regardless of which parashah happens to fall on each of those three weeks in a given year. Jeremiah is the obvious prophet to open that sequence, since his own book records, and in later chapters directly foretells, the very destruction the fast exists to mourn.
Recognizing this distinction matters for understanding the haftarah cycle as a whole: most weeks pair haftarah to parashah by shared theme, as every earlier reading in this account has shown, but a small number of fixed dates in the annual calendar override that ordinary logic entirely, assigning a haftarah to the date itself rather than to whatever parashah the lectionary happens to be reading that particular week.